Sl. Melton et al., REVIEW OF STABILITY MEASUREMENTS FOR FRYING OILS AND FRIED FOOD FLAVOR, Journal of the American Oil Chemists' Society, 71(12), 1994, pp. 1301-1308
Measurements of degradation in frying oils based on oil physical prope
rties and volatile and nonvolatile decomposition products were reviewe
d, Rapid methods by means of test kits were also considered, Factors t
hat affect the analysis of total polar components (TPC) in frying oils
were examined. Relationships between TPC, free fatty acid (FFA) conte
nt, Food Oil Sensor readings (FOS), color change (Delta E), oil fry li
fe and fried-food flavor were evaluated, Flavor scores for codfish, fr
ied in fresh and discarded commercial frying oil blends, were dependen
t upon individuals in the consumer panel (n = 77), Part (n = 29) of th
e panel preferred the flavor of fresh fat; others (n = 24) didn't; til
e rest (n = 24) had no preference, FFA, FOS and TPC were analyzed in t
wo soybean oils and in palm olein during a four-day period in which fr
ench fries were fried. Flavor score and volatiles of potatoes fried on
days 1 and 4 in each oil were also determined, TPC, FFA and FOS signi
ficantly increased (P < 0.05) in all oils during the frying period. TP
C and FFA were highest in the used palm olein, and flavor of potatoes
fried in palm olein on day 1 was less desirable than those fried in th
e soybean oils. Potatoes fried in day-1 oils had significantly higher
concentrations (P < 0.10) of several pyrazines and aldehydes than thos
e fried in day 4 oils.